# only return one paired numbers 
lst = [1,5,2,7,4,9]
target = 11


def twoSum(lst,tartget):
  objDict = {}
  for index,value in enumerate(lst):
      result = target - value
      if result in objDict:
          return [objDict.get(result),index]
      else:
          objDict[value] = index


if __name__ == '__main__':
  test = twoSum(lst,target)
  print(test)